Click on the flag for more information about Republic of Ireland REPUBLIC OF IRELANDTuesday, October 22, 2013, 23:50 (GMT + 9)

An invasion of the mauve stinger (Pelagia noctiluca) has killed off thousands farmed salmon off the Irish coasts, causing significant losses to Marine Harvest.

According to RTE, the invasion caused the loss of as much as 40 per cent of the stock at Co Mayo aquaculture farm, located off Clare island.

Although Marine Harvest was unable to confirm exact numbers, what it could say was that the loss was estimated to be 20,000 specimens.

The firm opted for an accelerated harvest at its Donegal aquaculture farm in order to minimize losses on its farmed stock.

Scientists connect the the jellyfish invasion to warmer sea waters. It is a phenomenon that has also been observed in other parts of the world.

Marine Harvest has been taking preventive measures such as giving its salmon less fish feed to keep them less active with gills covers closed as it worries about strandings of this jellyfish species from Donegal to Kerry.

A mauve stinger invasion was responsible for over EUR 1 million losses at a fish farm in Glenarm Bay, Co Antrim back in 2007, when some 120,000 fish were killed off.

The mauve stinger jellyfish belongs to the genus pelagia and is a jellyfish variety that is able to glow in the dark and is widely distributed in all warm and temperate waters of the world's oceans, including the Mediterranean Sea, Red Sea and Atlantic Ocean.

Jellyfish have been responsible for similar situations in Scotland. In 2011, both NexEra in Florida and Electricite de France SA had to halt their operations due to jellyfish invasions.

Marine Harvest has nine fish aquaculture farms along the western seaboard at locations from Donegal to Cork.